Film is the most diverse art form we know. It uses music, structure, writing, image, emotion and, very often, sex. Sometimes it uses the elements realistically, reflecting a feel of life that we all can recognize. Or it may use them in ways that imitate fantasies. We might laugh at the silliness with which they're presented, or recoil in dismay.

Especially the sex.

Eroticism has been the cornerstone of many a memorable film. It certainly will be in next weekend's "Fifty Shades of Grey," which has entered the national bloodstream with feverish intensity. It promises to be the biggest draw for female audiences since "Sex and the City" or "Twilight" left the screen.

If you watched the Super Bowl last weekend, you no doubt saw the film's provocative publicity campaign. Based on E.L. James' bestseller, a sexual cornucopia about a naive college graduate's sadomasochistic affair with the dashing billionaire Mr. Grey, the skin-baring movie is already a big ticket seller well in advance of Thursday night's opening screenings. So let's explore what all the fuss was about in comedic boundary-pushers and dark bodice-rippers.

There is hardly any nudity in "Belle de Jour," yet the intensely erotic 1967 masterpiece from director Luis Buñuel ran in a Manhattan art house for nearly a full year. Catherine Deneuve stars as Séverine, a Parisian beauty in a bland marriage to a handsome, sensitive young doctor. She joins a special brothel where bored women work for one or two afternoons a week, and becomes a belle de jour. Her clients remove her from the ordinary world of polite respect that her romantic husband offers, which is exactly what she wants.

In Buñuel's ironically detached fable, nearly all of Severine's adventures as a working girl occur off-screen, and those few scenes that happen on camera are largely hidden. One client presents her with an ornate box, opens it and asks her to use it. We never learn what was in the container, yet it became one of the most striking, baffling scenes in movie history, inspiring the mystery briefcase that Quentin Tarantino placed at the center of "Pulp Fiction."

The trailer for "Fifty Shades" has a puckish perversity that recalls the 2002 indie film "Secretary." It stars Maggie Gyllenhaal in a wonderful early performance as a masochistic young woman who takes a job as a secretary for the original Mr. Grey. James Spader, the era's go-to actor for kinky yuppie roles, hits a bull's-eye as Mr. E. Edward Grey, a lawyer with very particular proclivities. The film offers a funny portrait of the relationship between the controlling businessman and his protégée in pain and pleasure. While it is framed as a meeting between Little Red Riding Hood and the Big Bad Wolf, it's also an intelligent and psychologically effective story, pointedly examining the boundaries of compassion and trust that develop between the duo.

1983's scandalously funny "Risky Business," written and directed by Paul Brickman, introduced Tom Cruise to stardom as a college-bound Chicago teenager looking for fun at home while his parents take off for vacation. The situation gets quickly out of hand with the arrival of Rebecca De Mornay as a sensual, venal call girl who transforms his house into a brothel. Rarely has an aboveground film about a nice boy losing his virginity been so erotic, comedic and frightening at once. An excellent soundtrack including Prince, the Police, Talking Heads and the instrumental German band Tangerine Dream underscores the film's ping-pong between fine humor and genuine anxiety.

In Stanley Kubrick's 1999 "Eyes Wide Shut," Cruise follows the sexual fear factor to nightmarish calamity. He plays a New York City doctor married to an art curator (his wife at the time, Nicole Kidman) who shatters his self-confidence when she admits that she once almost cheated on him. Pushing himself on a nightlong odyssey of sexual and moral discovery, he enters a psychodrama of disturbing and risky encounters. Sexually propositioned time and again from every level of society, he encounters beastly evil, including a fearful, ornately choreographed orgy where every wealthy member wears Venetian or Greek masks.

"Her," writer/director Spike Jonze's 2013 futurist romantic drama, stars Joaquin Phoenix as a kindly writer who crafts personalized love mail for customers of his company, BeautifulHandwrittenLetters.com. As his wife pushes for divorce, the lonely, bereft man endures painfully awkward blind dates. Then he falls for Samantha, the humanlike consciousness of his new artificially intelligent computer operating system (voiced by Scarlett Johansson).

Set in the "uncanny valley" where human emotion and technology intersect, the film includes an extended scene of cyberphone sexual intimacy between the characters. Their flirtation reaches the point of sensually pleasurable moaning as the screen slowly fades to black. The next morning, Samantha confides, "Last night was amazing. It feels like something changed in me and there's no turning back. You woke me up." It's not an X-rated scene, but it's one of the most memorable bedroom scenes ever presented in mainstream films.